Abstract: This paper presents e-Class Personalized (e-CP), a new extension of the widely available open source Learning Content Management System e-Class. e-CP monitors interaction of the users of e-Class with its content and services and adapts the services to better suite the users’ interests and tasks. e-CP has been tested for over a year at the University of Patras e-Class server with over 20,000 users. It drew positive response by the user population that were exposed to this version of the leaning Content Management System. In this paper we discuss architectural decisions and evaluation results of e-CP